Case study Questions

1. How many breweries are present in each state?

# Create a seperate data frame to store state data 
### Note: This data set counts the district of columbia as a state
num_of_breweries_by_state <- data.frame(table(brewery_data$State))

##### Celia Banks #####
#Begin prepare an interactive geo map of breweries by state
#set the map
leaflet() %>% addTiles()

#add popup for brewery information
brewery_map <- cb_brewery %>% mutate(popup_info=paste(Name,"<br/>",City,"<br>",State,"<br>"))
#tweak the map with info layout, set circles smaller to enhance visual
leaflet() %>% addTiles() %>% addCircleMarkers(data=brewery_map, 
                                              lat=~Latitude, 
                                              lng=~Longitude, 
                                              radius=~1, 
                                              popup=~popup_info)

#End prepare an interactive geo map of breweries by state#

#corresponding distribution plot of breweries by state
ggplot(brewery_map, aes(x=as.factor(State), color="blue")) +
       geom_bar(color="blue") +
       ggtitle("Distribution of Breweries by State") +
       xlab("State") +
       geom_text(stat='count', aes(label=after_stat(count)), vjust=-.25) +
       theme(legend.position="none", axis.text.x = element_text(angle = 90)) +
       theme(plot.title = element_text(hjust = 0.5))

# Create data frame to access state count data 
num_of_brew_by_state <- data.frame(as.factor(brewery_map$State))

#corresponding distribution plot of breweries by region
ggplot(brewery_map, aes(x=as.factor(Region), color="green")) +
       geom_bar(color="green") +
       ggtitle("Distribution of Breweries by Region") +
       xlab("Region") +
       geom_text(stat='count', aes(label=after_stat(count)), vjust=-.25) +
       theme(legend.position="none", axis.text.x = element_text(angle = 90)) +
       theme(plot.title = element_text(hjust = 0.5))

##### END CB #####

The number of breweries per state are as follows: AK:7, AL:3, AR:2, AZ:11, CA:39, CO:47, CT:8, DC:1, DE:2, FL:15, GA:7, HI:4, IA:5, ID:5, IL:18, IN:22, KS:3, KY:4, LA:5, MA:23, MD:7, ME:9, MI:32, MN:12, MO:9, MS:2, MT:9, NC:19, ND:1, NE:5, NH:3, NJ:3, NM:4, NV:2, NY:15, OH:15, OK:6, OR:29, PA:25, RI:5, SC:4, SD:1, TN:3, TX:28, UT:4, VA:16, VT:10, WA:23, WI:20, WV:1, WY:4

2. Merge beer data with the breweries data. Print the first 6 observations and

#the last six observations to check the merged file

# Change column name of beer_data to match brewery_data to use as a primary key
colnames(beer_data)[5] <- "Brew_ID"

# Merge two data bases using merge
full_brew_data <- merge(brewery_data, beer_data, by="Brew_ID")

# Rename columns 2 and 5 that were changed during the merge
colnames(full_brew_data)[2] <- "Brewery"
colnames(full_brew_data)[5] <- "Beer_Name"

# Print first 6 and last 6 observations 
head(full_brew_data, n=6)

##   Brew_ID            Brewery        City State     Beer_Name Beer_ID   ABV IBU
## 1       1 NorthGate Brewing  Minneapolis    MN       Pumpion    2689 0.060  38
## 2       1 NorthGate Brewing  Minneapolis    MN    Stronghold    2688 0.060  25
## 3       1 NorthGate Brewing  Minneapolis    MN   Parapet ESB    2687 0.056  47
## 4       1 NorthGate Brewing  Minneapolis    MN  Get Together    2692 0.045  50
## 5       1 NorthGate Brewing  Minneapolis    MN Maggie's Leap    2691 0.049  26
## 6       1 NorthGate Brewing  Minneapolis    MN    Wall's End    2690 0.048  19
##                                 Style Ounces
## 1                         Pumpkin Ale     16
## 2                     American Porter     16
## 3 Extra Special / Strong Bitter (ESB)     16
## 4                        American IPA     16
## 5                  Milk / Sweet Stout     16
## 6                   English Brown Ale     16

tail(full_brew_data, n=6)

##      Brew_ID                       Brewery          City State
## 2405     556         Ukiah Brewing Company         Ukiah    CA
## 2406     557       Butternuts Beer and Ale Garrattsville    NY
## 2407     557       Butternuts Beer and Ale Garrattsville    NY
## 2408     557       Butternuts Beer and Ale Garrattsville    NY
## 2409     557       Butternuts Beer and Ale Garrattsville    NY
## 2410     558 Sleeping Lady Brewing Company     Anchorage    AK
##                      Beer_Name Beer_ID   ABV IBU                   Style Ounces
## 2405             Pilsner Ukiah      98 0.055  NA         German Pilsener     12
## 2406         Porkslap Pale Ale      49 0.043  NA American Pale Ale (APA)     12
## 2407           Snapperhead IPA      51 0.068  NA            American IPA     12
## 2408         Moo Thunder Stout      50 0.049  NA      Milk / Sweet Stout     12
## 2409  Heinnieweisse Weissebier      52 0.049  NA              Hefeweizen     12
## 2410 Urban Wilderness Pale Ale      30 0.049  NA        English Pale Ale     12

# Create CSV Files for head and tail 
head_output_csv <- "./output/head_beer_data.csv"
tail_output_csv <- "./output/tail_been_data.csv"
write.csv(head(full_brew_data, n=6), head_output_csv)
write.csv(tail(full_brew_data, n=6), tail_output_csv)

The first and last 6 observations were written to CSV files in the “output” file directory as well as printed in this file.

3. Address any NA values

# Create two new tables where one has only ABV with no <NA>'s and the other 
state_abv <- data.frame(State=full_brew_data$State, ABV=full_brew_data$ABV)
state_abv <- state_abv %>% drop_na(ABV)

# Do the same for IBU 
state_ibu <- data.frame(State=full_brew_data$State, IBU=full_brew_data$IBU)
state_ibu <- state_ibu %>% drop_na(IBU)

Multiple Data sets were created throught to handle specific questions. For example; if the question asked for the comparison between ABV and IBU then any beer with an NA for either would be dropped. For a question where ABV or IBU was not needed, then all data would be retained.

4. Compute the median alcohol content and international bitterness unit for each

##state. Plot a bar chart

# Find the average ABV for the state_abv table 
avg_state_abv <- ddply(state_abv, .(State), function(x) median(x$ABV))
colnames(avg_state_abv)[2] <- "Median_ABV" # Rename the column
# Drop DC. It's not a state....yet
avg_state_abv <- avg_state_abv[-c(8),] # DC is equal to position 8 on the table 
# Order the states by Decending ABV content 
avg_state_abv <- avg_state_abv[order(avg_state_abv$Median_ABV, decreasing=TRUE),]

# Find Average IBU
avg_state_ibu <- ddply(state_ibu, .(State), function(x) median(x$IBU))
colnames(avg_state_ibu)[2] <- "Median_IBU" # Rename column
# Order the states by IBU Decending 
avg_state_ibu <- avg_state_ibu[order(avg_state_ibu$Median_IBU, decreasing=TRUE),]

# Plot Average Alcohol by Volume per state
ggplot(avg_state_abv, aes(x=reorder(State, desc(Median_ABV)), y=Median_ABV, fill=State)) + 
       geom_col(show.legend = FALSE, width=.9, position="dodge") +
       ggtitle("Median ABV per State") +
       xlab("State") + 
       ylab("Median Alcohol by Volume")

# Plot Average International Bitterness Unit per State 
ggplot(avg_state_ibu, aes(x=reorder(State, desc(Median_IBU)), y=Median_IBU, fill=State)) + 
       geom_col(show.legend = FALSE, width=.9, position="dodge") +
       ggtitle("Median IBU per State") + 
       xlab("State") + 
       ylab("Median IBU")

4.1 Additional data

##### Celia Code #####
merge_bb <- merge(cb_beer, cb_brewery, by.x="Brewery_id", by.y="Brew_ID")
#Drop latitude and longitude columns as no longer needed
drop <- c("Latitude","Longitude")

cb_merged_bb <- merge_bb[,!(names(merge_bb) %in% drop)]

#rename columns to avoid confusion
#cb_merged_bb <- cb_merged_bb %>% rename(Beer_Name = Name.x, Brewery_Name = Name.y)
### RAH - used a different method of renaming columns ###
colnames(cb_merged_bb)[2] <- "Beer_Name"
colnames(cb_merged_bb)[8] <- "Brewery_Name"
### End RAH ###

#get count of breweries in each state
brewery_count <- aggregate(Brewery_id ~ State, cb_merged_bb, sum)
aggregate(cb_merged_bb$Brewery_id, by=list(Category=cb_merged_bb$State), FUN=sum)

##    Category     x
## 1        AK  8363
## 2        AL  4208
## 3        AR   820
## 4        AZ  9815
## 5        CA 46773
## 6        CO 65472
## 7        CT  9222
## 8        DC  1824
## 9        DE   857
## 10       FL 15781
## 11       GA  4662
## 12       HI  8521
## 13       IA 11756
## 14       ID  8605
## 15       IL 15231
## 16       IN 12855
## 17       KS  2899
## 18       KY  1334
## 19       LA  4817
## 20       MA 21195
## 21       MD  4789
## 22       ME  8142
## 23       MI 15130
## 24       MN  8687
## 25       MO 10063
## 26       MS  1698
## 27       MT 16604
## 28       NC 20439
## 29       ND  1008
## 30       NE  8855
## 31       NH  1508
## 32       NJ  1892
## 33       NM  5103
## 34       NV  4653
## 35       NY 19400
## 36       OH  7974
## 37       OK  5483
## 38       OR 26890
## 39       PA 26078
## 40       RI  5802
## 41       SC  3108
## 42       SD  1491
## 43       TN  2073
## 44       TX 25427
## 45       UT  7289
## 46       VA 11011
## 47       VT  6459
## 48       WA 25471
## 49       WI 18638
## 50       WV   314
## 51       WY  4438

#impute the rows with zeroes
cb_merged_bb$ABV[is.na(cb_merged_bb$ABV)] <- 0
cb_merged_bb$IBU[is.na(cb_merged_bb$IBU)] <- 0

#compute median ABV and IBU for each state
cb_medianABV <- aggregate(ABV ~ State + Region, cb_merged_bb, median)
cb_medianIBU <- aggregate(IBU ~ State + Region, cb_merged_bb, median)

#merge the medians dataframes
cb_mergeABVIBU <- merge(cb_medianABV, cb_medianIBU, by="State")
drop <- c("Region.y")
cb_mergeABVIBU = merge_bb[,!(names(merge_bb) %in% drop)]

#Visualize ABV v IBU medians by state and by region
options(scipen = 999)
cb_mergeABVIBU <- as.data.frame(cb_mergeABVIBU)

#by state
ggplot(cb_mergeABVIBU, aes(ABV, IBU, color=State)) +
       geom_point(show.legend = FALSE) +
       facet_wrap(vars(State))

## Warning: Removed 1005 rows containing missing values (geom_point).

#by region
ggplot(cb_mergeABVIBU, aes(ABV, IBU, color=Region)) +
       geom_point() +
       facet_wrap(vars(Region))

## Warning: Removed 1005 rows containing missing values (geom_point).

##### END #####

Celia was able to create a ABV vs IBU for state and regions. This gave us additional data to make assumptions from.

5. Which state has the the Max ABV. Which has the

# Get the State with the highest average ABV
state_max_abv <- full_brew_data[which.max(full_brew_data$ABV),] # CO
state_max_abv[c(4,7)]

##     State   ABV
## 384    CO 0.128

# Get the State with the highest average IBU
state_max_ibu <- full_brew_data[which.max(full_brew_data$IBU),] # OR
state_max_ibu[c(4,8)]

##      State IBU
## 1857    OR 138

Colorado has the highest percentage of alcohal by volume while Oregon has the highest IBU. Keep in mind the question was asking for the max and not the max average.

6. Comment on the Summary stats and distribution of the ABV variable

# Get summary and disply a histogram and boxplot
summary(state_abv)

##     State                ABV         
##  Length:2348        Min.   :0.00100  
##  Class :character   1st Qu.:0.05000  
##  Mode  :character   Median :0.05600  
##                     Mean   :0.05977  
##                     3rd Qu.:0.06700  
##                     Max.   :0.12800

ggplot(state_abv, aes(x=ABV)) + geom_histogram() # Right Skewness

## `stat_bin()` using `bins = 30`. Pick better value with `binwidth`.

ggplot(state_abv, aes(x=ABV)) + geom_boxplot()

Most of the beer created fell inbetween 5.0% - 6.7% ABV with a mean of 5.9% and a median of 5.6%. There is also a noticeable right skewness to the distribution.

##7. Is there an apparent relationship between the bitterness of the beer and its alcoholic content?

# Create a new data frame from the beer data that removes rows that have <NA> in 
# the ABV and IBU columns
beer_data_no_na <- beer_data
beer_data_no_na <- beer_data_no_na %>% drop_na(ABV)
beer_data_no_na <- beer_data_no_na %>% drop_na(IBU)

# Scatter plot to show raw data 
ggplot(beer_data_no_na, aes(x=ABV, y=IBU, colour=Style)) + 
       geom_point(show.legend = FALSE) + 
       ggtitle("ABV vs IBU") +
       xlab("ABV in %") + 
       ylab("IBU")

# Plot a smooth curve to see a more "linear" pattern 
ggplot(beer_data_no_na, aes(x=ABV, y=IBU)) + 
       geom_smooth() +
       ggtitle("ABV vs IBU") + 
       xlab("ABV in %") + 
       ylab("IBU")

## `geom_smooth()` using method = 'gam' and formula 'y ~ s(x, bs = "cs")'

According to the charts there is a obvious positive correlation between ABV and IBU. After further investigation on why this could be, we found many answers but not one that stood out. The most common answer was that the longeryou boil hops to increase the IBU, the alcohol (ABV) goes up to ballance the bitterness.

8. investigate the difference with respect to IBU and ABV between IPAs (India Pale Ales)

#and other types of Ale. Use KNN.

# Create a data frame with only IPA's
#df1[grep("dog",df1$type),]
ipa_beers <- beer_data_no_na[grep("IPA",beer_data_no_na$Style),]
# Change the Sytle column to only have the value of IPA for easier model training
ipa_beers$Style <- "IPA"

ales_beer <- beer_data_no_na[grep("Ale",beer_data_no_na$Style),]
# Change the Sytle column to only have the value of Ale for easier model training
ales_beer$Style <- "Ale"

# Combine the two data sets 
ipas_and_ales <- rbind(ipa_beers, ales_beer)

# plot the data to get an initial view of the data
ggplot(ipas_and_ales, aes(x=ABV, y=IBU, colour=Style)) + geom_point()

# Create empty train and test data frames
ipas_and_ales_train <- ipas_and_ales # train data needs to be a duplicate of orig
ipas_and_ales_test <- data.frame()

# Split 70/30 (Train/Test) #
# Find the 30% value 
samples_to_take <- round(as.numeric(nrow(ipas_and_ales_train)*.3), digits=0)
for (row in 1:samples_to_take) {
  tmp_row <- sample_n(ipas_and_ales_train, 1) # Take sample
  # Add Sample to test data
  ipas_and_ales_test <- ipas_and_ales_test %>% rbind(tmp_row)
  # Remove Sample from train data
  ipas_and_ales_train <- ipas_and_ales_train[!(ipas_and_ales_train$Beer_ID==tmp_row$Beer_ID),]
}

# Declare how many interations to run
k_iterations <- 20

# find an optimal K value for the KNN model
style_accuracy <- data.frame(accuracy=numeric(k_iterations), k=numeric(k_iterations))
for (iter in 1:k_iterations) {
  # Note: [,c(3,4)] represent the ABV and IBU columns
  style_class <- knn(ipas_and_ales_train[,c(3,4)], 
                     ipas_and_ales_test[,c(3,4)],
                     ipas_and_ales_train$Style,
                     prob=TRUE, 
                     k=iter)
  table(ipas_and_ales_test$Style, style_class)
  cm <- confusionMatrix(table(ipas_and_ales_test$Style, style_class))
  style_accuracy$accuracy[iter] <- cm$overall[1]
  style_accuracy$k[iter] <- iter
}

#plot(style_accuracy$k, style_accuracy$accuracy, type="l", xlab="k")
plot_ly(style_accuracy, x=style_accuracy$k, y=style_accuracy$accuracy, 
        type="scatter", mode="lines")

# On average this loop gives me an optimal k level of k=5,6,7
# Use 6 as the choice k
optimal_k <- 6

################################################################################
# START Multi-Class prediction confidence with Heatmap
# Use existing Training and Test Data Frames 

# assign IBU column values as numeric to keep it the same as ABV
ipas_and_ales_train$IBU <- as.numeric(ipas_and_ales_train$IBU)
ipas_and_ales_test$IBU <- as.numeric(ipas_and_ales_test$IBU)
# classification models require the outcome to be of type factor()
ipas_and_ales_train$Style <- as.factor(ipas_and_ales_train$Style)
ipas_and_ales_test$Style <- as.factor(ipas_and_ales_test$Style)

# grid config
grid_mesh_size <- .02
grid_margin <- 1

# Create a mesh grid to run the model
grid_l_min <- min(ipas_and_ales$IBU) - grid_margin
grid_l_max <- max(ipas_and_ales$IBU) + grid_margin
grid_w_min <- min(ipas_and_ales$ABV) - grid_margin
grid_w_max <- max(ipas_and_ales$ABV) + grid_margin
grid_l_range <- seq(grid_l_min, grid_l_max, grid_mesh_size)
grid_w_range <- seq(grid_w_min, grid_w_max, grid_mesh_size)
beer_grid <- meshgrid(grid_l_range, grid_w_range)
grid_ll <- beer_grid$X
grid_ww <- beer_grid$Y

# Create (another) classifier and run on the grid
# Reuse the optimal k-value from ealier for the neighbors argument
beer_model <- nearest_neighbor(neighbors=optimal_k, weight_func="inv") %>%
  set_engine("kknn") %>%
  set_mode("classification") %>% 
  fit(formula=Style ~ ABV + IBU, data=ipas_and_ales_train)

grid_ll_1 <- matrix(grid_ll, length(grid_ll), 1)
grid_ww_1 <- matrix(grid_ww, length(grid_ww), 1)
grid_final <- data.frame(grid_ll_1, grid_ww_1)

colnames(grid_final) <- c("IBU", "ABV")

grid_pred <- beer_model %>% predict(grid_final, type='prob')

dim_value <- dim(grid_ll)

prob_ipa <- matrix(grid_pred$.pred_IPA, dim_value[1], dim_value[2])
prob_ale <- matrix(grid_pred$.pred_Ale, dim_value[1], dim_value[2])

# Get the classifier Confidence 
ale_ipa_z <- array(c(prob_ipa, prob_ale), dim=c(dim_value[1], dim_value[2],3))
diff <- aaply(ale_ipa_z, c(1,2), max) - (aaply(ale_ipa_z, c(1,2), sum) - 
                                           aaply(ale_ipa_z, c(1,2), max))

# Overlay the heatmap of the confidence on the scatter plot of the example 
ale_ipa_fig <- plot_ly()
ale_ipa_fig <- ale_ipa_fig %>% 
               add_trace(data=ipas_and_ales_test, 
                         y= ~ABV, 
                         x= ~IBU, 
                         symbol= ~Style, 
                         split= ~Style,
                         symbols= c('square-dot', 'circle-dot'),
                         type= 'scatter',
                         mode= 'markers',
                         marker= list(size=12, 
                                      line=list(width=1.5), 
                                      color='lightyellow')) %>%
               layout(title="Prediction Confidence on Test Split")
ale_ipa_fig <- ale_ipa_fig %>% add_trace(x=grid_l_range, y=grid_w_range, z=diff, type='heatmap')
ale_ipa_fig

Using KNN and plotly to generate the above graph you can see the relationship of Ales to IPAs. If you zoom into the chart you will be able to see that below 60 IBU the beer is predicted to be an Ale, but as IBU approached 60 and upward the beer is likely to be classified as an IPA. With ABV having a positive correlation with IBU the ABV is less of a factor in determining the beer Style. You need to zoom in to get the full affect.

9. Additional usefule data

# My goal here is to find the most popular style of beer for each region 
#
# Create a new data set based on the fully merged data at the start 
style_by_region <- data.frame(full_brew_data)

# Remove NA values for City, State, and Style 
#state_ibu <- state_ibu %>% drop_na(IBU)
style_by_region <- style_by_region %>% drop_na(City)
style_by_region <- style_by_region %>% drop_na(State)
style_by_region <- style_by_region %>% drop_na(Style)

# Add region data by left joining from brewery_map using Brew_ID as primary key
style_by_region <- left_join(style_by_region, brewery_map[,c("Brew_ID", "Region")])

## Joining, by = "Brew_ID"

# Drop the columns not needed to make it easier to read
style_by_region <- data.frame(style_by_region$Style, style_by_region$Region)

# Lets break up the data by region 
style_by_midwest <- filter(style_by_region, 
                           style_by_region$style_by_region.Region == "Midwest")
style_by_northeast <- filter(style_by_region, 
                             style_by_region$style_by_region.Region == "Northeast")
style_by_southeast <- filter(style_by_region, 
                             style_by_region$style_by_region.Region == "Southeast")
style_by_southwest <- filter(style_by_region, 
                             style_by_region$style_by_region.Region == "Southwest")
style_by_west <- filter(style_by_region, 
                        style_by_region$style_by_region.Region == "West")

# Find the top 5 styles per region
style_by_midwest <- data.frame(table(style_by_midwest$style_by_region.Style))
style_by_midwest <- style_by_midwest[order(style_by_midwest$Freq, decreasing = TRUE),]
style_by_midwest <- head(style_by_midwest, n=5)

style_by_northeast <- data.frame(table(style_by_northeast$style_by_region.Style))
style_by_northeast <- style_by_northeast[order(style_by_northeast$Freq, decreasing = TRUE),]
style_by_northeast <- head(style_by_northeast, n=5)

style_by_southeast <- data.frame(table(style_by_southeast$style_by_region.Style))
style_by_southeast <- style_by_southeast[order(style_by_southeast$Freq, decreasing = TRUE),]
style_by_southeast <- head(style_by_southeast, n=5)

style_by_southwest <- data.frame(table(style_by_southwest$style_by_region.Style))
style_by_southwest <- style_by_southwest[order(style_by_southwest$Freq, decreasing = TRUE),]
style_by_southwest <- head(style_by_southwest, n=5)

style_by_west <- data.frame(table(style_by_west$style_by_region.Style))
style_by_west <- style_by_west[order(style_by_west$Freq, decreasing = TRUE),]
style_by_west <- head(style_by_west, n=5)

# Create some bar charts to show results 
# Midwest
ggplot(style_by_midwest, aes(x=Var1, y=Freq, fill=Var1)) +
       geom_col(show.legend = FALSE) +
       ggtitle("Top 5 Styles for Midwest") +
       xlab("Style") + ylab("Number of Style")

# Northeast
ggplot(style_by_northeast, aes(x=Var1, y=Freq, fill=Var1)) +
       geom_col(show.legend = FALSE) +
       ggtitle("Top 5 Styles for Northeast") +
       xlab("Style") + ylab("Number of Style")

# Southeast
ggplot(style_by_southeast, aes(x=Var1, y=Freq, fill=Var1)) +
       geom_col(show.legend = FALSE) +
       ggtitle("Top 5 Styles for Southeast") +
       xlab("Style") + ylab("Number of Style")

# Southwest
ggplot(style_by_southwest, aes(x=Var1, y=Freq, fill=Var1)) +
       geom_col(show.legend = FALSE) +
       ggtitle("Top 5 Styles for Southwest") +
       xlab("Style") + ylab("Number of Style")

# West
ggplot(style_by_west, aes(x=Var1, y=Freq, fill=Var1)) +
       geom_col(show.legend = FALSE) +
       ggtitle("Top 5 Styles for West") +
       xlab("Style") + ylab("Number of Style")

The results from my research shows two points. 1. The top two styles for every region is an “American IPA” and an “American Pale Ale”. 2. The third most popular style of beer is what is different between the regions. Results as follows for the 3rd most popular of each region:

Midwest - American Pale Wheat Ale, Northeast - American Double / Imperial IPA, Southeast - American Blonde Ale, SouthWest - American Amber / Red Ale, West - American Amber /Red Ale

Case-One-Study

Setup